1. Field of the Invention
The present invention is broadly concerned with improved multiple-station article processing apparatus such as that used in the box-making industry for the production of box blanks. More particularly, it is concerned with equipment of this type which preferably includes a selectively operable braking assembly operatively associated with the drive train of the equipment, which serves to engage and brake the drive train during equipment makeready adjustments in order to prevent unintended movement of the drive train which can have the effect of improperly altering the timed operational relationship of the various stations of the apparatus.
2. Description of the Prior Art
Box-making plants universally make use of large equipment designed for the high speed fabrication of box blanks from starting paperboard sheets. In general, these machines are operable to individually feed paperboard sheets from a stack thereof into a scoring and slotting station where the sheets are appropriately scored and slotted to form the side panels and end flaps required for box blanks. Thereafter, the finished blanks are delivered to a counting and stacking station, for ultimate delivery to the end users.
U.S. Pat. No. 5,181,899 (incorporated by reference herein) describes an improved box blank fabricating apparatus especially designed for very rapid changeover and makeready operations. To this end, the various stations of the apparatus are operated in a timed relationship with each other via a drive train including a motor, line shaft, gear boxes and shafts supporting the operative components of the unit (e.g., scoring and slotting wheels). In addition, the equipment described in the '899 patent is provided with novel adjustment apparatus allowing rapid, accurate alteration of the positions of the fixed and adjustable knives of the slotting wheels, all without the necessity of individual adjustment of each wheel. Such knife adjustment can be automatically controlled, and is accomplished by means of compensators operatively secured with the scoring and slotting shafts, with an intermediate transfer gear between each associated scoring and slotting wheel.
In experimental practice with the apparatus described in this patent, it has been determined that makeready adjustments involving changes in slotter wheel knife positions can have the unintended effect of slightly advancing or retarding the drive train of the machine. This is a problem, because such unintended rotation of the drive train components has the effect of altering the timing between the various stations of the apparatus. As a consequence, while knife adjustments may be properly made, the apparatus will still produce improperly configured blanks, owing to the out-of-time operation of the equipment. Therefore, the machine must again be stopped, and the drive train rezeroed before proper operation can commence.
There is accordingly a need in the art for an improved multiple-station article processing apparatus having adjustable processing station(s) wherein mistiming of station operation is prevented during adjustments of the operating components of the stations.